Pino Alessandra, Vaccalluzzo Amanda, Solieri Lisa, Romeo Flora V, Todaro Aldo, Caggia Cinzia, Arroyo-López Francisco Noé, Bautista-Gallego Joaquin, Randazzo Cinzia L
Department of Agricultural, Food and Environment, University of Catania, Catania, Italy.
Department of Life Sciences, University of Modena and Reggio Emilia, Reggio Emilia, Italy.
Front Microbiol. 2019 Feb 8;10:174. doi: 10.3389/fmicb.2019.00174. eCollection 2019.
In the present study, the β-glucosidase positive strain F3. 3 was used as starter during the fermentation of Sicilian table olives (Nocellara Etnea cultivar) at two different salt concentrations (5 and 8%), in order to accelerate the debittering process. The latter was monitored through the increase of hydroxytyrosol compound. In addition, the potential probiotic N24 strain was added after 60 days of fermentation. Un-inoculated brine samples at 5 and 8% of salt were used as control. The fermentation was monitored till 120 days through physico-chemical and microbiological analyses. In addition, volatile organic compounds and sensorial analyses were performed during the process and at the end of the fermentation, respectively. Lactic acid bacteria and yeasts were, in depth, studied by molecular methods and the occurrence of the potential probiotic N24 strain in the final products was determined. Results highlighted that inoculated brines exhibited a higher acidification and debittering rate than control ones. In addition, inoculated brines at 5% of salt exhibited higher polyphenols (hydoxytyrosol, tyrosol, and verbascoside) content compared to samples at 8% of NaCl, suggesting a stronger oleuropeinolytic activity of the starter at low salt concentration. Lactobacilli and yeasts dominated during the fermentation process, with the highest occurrence of and , respectively. Moreover, the potential probiotic N24 strain was able to survive in the final product. Hence, the sequential inoculum of beta-glucosidase positive and potential probiotic strains could be proposed as a suitable technology to produce low salt Sicilian table olives.
在本研究中，β-葡萄糖苷酶阳性菌株F3.3被用作西西里食用橄榄（诺塞拉埃特纳品种）在两种不同盐浓度（5%和8%）下发酵的起始菌株，以加速脱苦过程。脱苦过程通过羟基酪醇化合物的增加来监测。此外，在发酵60天后添加了潜在的益生菌N24菌株。以5%和8%盐浓度的未接种盐水样品作为对照。通过理化和微生物分析对发酵过程进行监测，直至120天。此外，分别在发酵过程中和发酵结束时进行挥发性有机化合物和感官分析。通过分子方法深入研究了乳酸菌和酵母菌，并测定了最终产品中潜在益生菌N24菌株的存在情况。结果表明，接种的盐水比对照盐水表现出更高的酸化和脱苦速率。此外，5%盐浓度的接种盐水比8%氯化钠浓度的样品表现出更高的多酚（羟基酪醇、酪醇和毛蕊花糖苷）含量，表明起始菌株在低盐浓度下具有更强的橄榄苦苷分解活性。乳酸菌和酵母菌在发酵过程中占主导地位，分别以最高发生率出现。此外，潜在的益生菌N24菌株能够在最终产品中存活。因此，β-葡萄糖苷酶阳性菌株和潜在益生菌菌株的顺序接种可被认为是生产低盐西西里食用橄榄的合适技术。
